Limbs, including legs, knees, shins, ankles, feet, toes, arms, elbows, forearms, wrists, hands and fingers, can incur pain and discomfort from various afflictions, such as accidents, skin eruptions and deformities.
Foot and toe deformities have been noted from childhood to adolescence and throughout adulthood. Such deformities include bunions, hammertoes, and mallet toes, all of which can lead to pain and/or discomfort for the afflicted individual. Conditions which can develop secondary to these are corns, calluses, plantar warts and blisters. These afflictions are equally painful or discomfortable as the prior afflictions.
Corns are a painful hyperkeratosis, found principally over prominent toe joints and between toes. There are two common types of corns: Heloma Durum and Heloma Molle. Heloma Durum (hard corn) is a hyperkeratotic lesion which appears over a bony prominence and may have a deep nucleus. These corns are normally very tender and painful. The Heloma Molle (soft corn) is a hyperkeratotic lesion which is found between the toes. The soft corn results from pressure exerted between adjacent toes and is soft due to moisture between the toes.
A callus may be a difuse or circumscribed area of hyperkeratosis at a site of repeated pressure and friction. In cases where there is a forefoot imbalance the plantar callus may be found where the metatarsal heads are most prominent.
Plantar warts are simple papilomas caused by a virus. Plantar warts differ from calluses and are not necessarily found over bony prominences. They may be sharply circumscribed with their edges clearly demarcated from the surrounding skin. Their center is darker than the surrounding skin and their may have a mosine appearance. Warts are usually painful to squeezing and often exhibit pain from the pressure of walking.
Hammertoe is a fixed flexion deformity of the proximal interphalangeal joint. This condition is most commonly found in the lesser toes. Other toe deformities include mallet toe which is a flexion deformity of the distal interphalangeal joint.
A blister is a collection of fluid below or within the epidermis caused by excessive frictional forces exerted on the epidermal layer.
Hallux abducto valgus (bunion) is a condition which is characterized by enlargement of the big toe joint and migration of the toe towards the midline of the foot. Heredity is a strong influence in the development of bunions. Bunion deformities are aggravated by improper shoes and a biomechanical imbalance in the rear portion of the foot. A soft tissue bursae may develop over the prominence of the bunion deformity. Bunions typically cannot be cured by using a footcare device; however, the symptoms can be relieved. In some cases, the bunion may be treated with corrective surgery. Pressure and friction over the bunion may cause symptoms such as swelling, inflammation, and development of hyperkeratotic lesions. Bunions secondarily may cause calluses under adjacent metatarsal heads, hammertoes, and corns.
Numerous devices or inserts have been developed to provide cushioning for foot discomfort, including toe-crest pads (i.e. toe-lift pads), heel cushions and heel liners, half-insole or metatarsal pads, full-length and three quarter (3/4) length insoles, arch supports, toe caps, toe separators and molded or die-cut sheet cushions for corns, calluses, blisters, bunions and plantar warts. Toe crest pads are typically worn under the toe. Heel cushions are used to treat conditions such as plantar fascitis, a painful area felt under the heel or calcaneal bursitis (a general pain over the whole calcaneal pad). Heel liners are designed to eliminate shoe slippage, take up room in the shoe and prevent snagging of hose or socks. Half-insoles or metatarsal pads are used for protection in the forefoot region, primarily by women to prevent pain or to prevent the foot from sliding in the shoe. Insoles or innersoles are used for cushioning and shock attenuation, for relief of aching feet and for relief of back pain. Arch supports have been used to relieve foot and leg discomfort caused by flat arches, low arches, high arches, over supination, over-pronation, valgus, varus and other conditions, by realigning the foot to achieve a natural positioning of bone structures. Custom molded shoes, toe caps, felt, moleskin or foam cushions with adhesives, splints, toe separators, or a foam and/or felt devices with toe loops have been used for the treatment of corns, calluses, plantar warts, blisters and bunions.
Most of these devices suffer various disadvantages. For example, bunion devices such as molded plastic splints and rubber shields are generally too large to fit into some shoes and cause discomfort instead of pain relief. Corn, callus, blister, plantar wart and some hammertoe products have the disadvantage of not being reusable after daily use, of lacking the ability to confom to the foot or toe contour, or of inducing maceration of the skin. Devices such as toe crest pads, heel cushions, heel liners, half insoles, metatarsal pads, full length insoles, 3/4 length insoles and arch supports typically utilize various cushioning materials in combination with adhesives or adhesive tapes to minimize slippage of the device with footwear. This approach has the disadvantage of requiring completely separate materials (i.e. cushioning and adhesive) to achieve the separate functions of cushioning and attachment to the article of footwear. Further, upon washing, the adhesive used in such devices tends to deteriorate rapidly. Further, most of these materials will induce maceration or softening of the skin.
Organopolysiloxane elastomers are taught in U.S. Pat. Nos. 3,445,420; 3,884,866; and 4,162,243. Such known polysiloxane compositions lack the combination of the requisite tack, or hardness, tensile strength, elongation and/or tear strength for the above applications.
Therefore, research was conducted to make a polysiloxane cushioning material which could serve the dual function of providing both attachment of the device to the limb or to an article of footwear and cushioning of the limb, with little or no maceration of the skin.